1) Find the standard enthalpy of cyanamide (CH3N2 (s) ) from its heat of combustion to CO2 and H2O of -741.40kJ/mol.
2) Calculate delta S if the temperature of 2.50mol of an ideal gas with Cv = 5/2R is increased from 160K to 675k under conditions of
a. constant pressure
b. constant volume

1) One mole of an ideal gas is changed from 273.15K and 2 atm to 233.15K and 0.4 atm. Calculate delta S for this change in state.
2) Arrange the following chemicals in order of increasing entropy at STP.
n - pentane (g)
methanol ( l)
ethanol (l)
ethanol (g)

Question:
The volume of 1 mole of an ideal, monoatomic gas which is initially at 2 atm, 25"C, and 12.2L is doubled by the following paths:
a) isothermal expansion;
b) adiabatic expansion;
c) expansion along a path defined by P=0. 2V+b, where p is in atm, Vis in L/mol, and b is a constant.
Assume that all paths are

The sublimation temperature of solid CO2 is -78.5 "C at 1 atm pressure. At what minimum pressure must gaseous CO2 be stored in a fire extinguisher at 25 degrees C to ensure that some "snow" is produced when the gas is released to atmospheric pressure?
Use mico JT = 1.3 for CO2 and assume that it is independent of pressure and

An ideal gas undergoes a reversible isothermal expansion from an initial volume V1 to a final volume that is ten times greater, and in this process it does 10kJ of work, The initial pressure was 10^6 Nm^-2.
a) Find V1
b) If there were initially 2 moles of the gas, what was its initial temperature?

Consider a physical explanation for the difference of vapour pressure of miscible and immiscible solutions. For immiscible the total vapour pressure is equal to the sum of the pressure from the pure liquids but and miscible liquids pressure vapour pressure follows raoults law. What is the physical justification for this?

I have a question about relations for a process even though I am unsure about the scope of this. Still I wonder about a mathematical relation for the following:
I wonder about how one defines mathematically that a process is reversible for a process that has both pressure and temperature differences from definition of total e

Question #1
A 25.000g sample of unknown metal is heated to 99.5 degrees Celsius and added to 50.0mL of water in a calorimeter, which has an initial temperature of 22.o degrees Celsius (density of water is 0.99780 g/mL. The temperature of the calorimeter increases to a maximum temperature of 33.5 degrees Celsius. The heat capa

1.
For the reaction
2 NO(g) + O2(g) -->2 NO2(g)
deltaH = -126.0 kJ at 25C.
(a) Calculate the amount of heat transferred when 333 g of NO(g) reacts with O2(g) at 25C and 1 atm.
(b) Does this heat flow into the system or does it flow to the surroundings?
(c) Is this reaction exothermic or endothermic?
2.
If 8675 J of

The equation of state of one mole of a van der Waals gas is given by
(P+a/(v^2))(V-b) = RT
with a and b are constants.
a) Calculate the work W in an isothermal reversible process when volume changes from V1 to V2.
b) Using the energy equation, show that (du/dV) = a/v^2
c) Calculate the change in internal energy U in th

1-HgO(s) Hg(l) + O2(g)
Consider the unbalanced equation above. A sample of impure mercury(II) oxide is heated and the HgO decomposed completely. If 680. mL of O2 is collected by displacement of water at a barometric pressure of 680.0 mm Hg and 25.0°C, what mass of HgO was originally present? The vapor pressure of water is 23.

1. Consider the phase change:
C(graphite) <---> C(diamond)
Given that delta_rG^o/Jmol^-1 = 1895 + 3.363T, calculate the enthalpy and entropy. Calculate the pressure at which diamond and graphite are in equilibrium with each other at 25 degree Celsius. Take the density of diamond and graphite to be 3.51 g/cm^3 and 2.25 g/c

Liquid ammonia, NH3(l), was once used in home refrigerators as the heat transfer fluid. The specific heat of the liquid is 4.7 J/g.K and that of the vapor is 2.2 J/g.K. The enthalpy of vaporization is 23.33 kJ/mol at the boiling point. If you heat 12 kg of liquid ammonia from
-50.0 °C to its boiling point of -33.3 °C, allow i

Hello,
How do I determine the change in boiling point of methyl ethyl ketone (MEK) when initially at atmospheric pressure ---- therefore B.P. - 79.6 oC ------ and then under -27 inches of vacuum pressure? What would be the new B.P. of the MEK?
Please please explain how to do this.

Thermal Interactions
Part 1:
In an insulated container, you mix 200. g of water at 80ºC with 100. g of water at 20ºC. After mixing, the temperature of the water is 60ºC.
a. How much did the temperature of the hot water change? How much did the temperature of the cold water change? Compare the magnitudes (positive values) o

Estimate the enthalpy change for the combustion of one mole of ethanol (C2H5OH) using average bond dissociation enthalpies (in KJ/mol) for C-H: 413, O-H: 463, C-O: 358, C-C: 154, C=O: 122, and O=O: 498. Then use the estimate to calculate the heat of formation of ethanol from the heats of formation (in KJ/mol) of CO2: 394, and H2

1. Some octahedral metal complexes are known to undergo the dissociative mechanism shown below. Consider both a d8 strong field complex and a d8 weak field complex. Would either of these complexes be expected to undergo this type of mechanism? Explain your reasoning. Assume P < 0.8d(delta)o for the strong field case.
2. List

You are out camping with your family and you decide that you would heat some water for cooking your food. The pot you use is made from aluminum (heat capacity, s, = 0.902 J/g@EC). The pot has a mass of 675.6 g and a capacity of 1.356 L. You are going to heat water (s = 4.184 J/g degrees C) starting from ice (s = 36.93 J/mol degr

When a 3.88 g sample of solid ammonium nitrate dissolves in 60.0 g of water in a coffee-cup calorimeter, the temperature drops from 23.0 degrees Celsius to 18.4 degrees Celsius. Calculate delta H in kJ per mole of NH4NO3 for the solution process. Assume the specific heat of the solution is the same as that of pure water.
Ple

You want to heat a pot of water. If you assume that the pot is made out of iron, which has a mass of 11.00 kg with a specific heat capacity (s) of 0.4498 J/g C, and you have exactly 1 L of pure water, starting with the water at exactly 15C and wanting to get the water to boil, how many grams of butane gas (C4H10) will need to b

You have a system with a movable piston that is isolated. The reaction inside the system is under adiabatic conditions. When the reaction (the burning of butane in oxygen) is started, the distance the piston traverses is 30.00 cm at 1.000 atm of pressure, the diameter of the piston is 8.000 cm. If you take 15.00 mg of butane an

You have a sample of a substance at a given temperature and the temperature of a substance is proportional to the kinetic energy of the molecules. However, do all the molecules have the same energy? Fully explain.
(Answer provided in less than 100 words.)

As all of you are aware, there is a big push to use ethanol (C2H6O) as a source of fuel for our automobiles, instead of gasoline. Assuming that gasoline can be adequately represented by octane (C8H10), determine how reasonable it is. That is, will individuals actually save any money using ethanol (at approximately $0.83/L) as